Figure 1 is an illustration of diatonic modes on guitar fingerboard. Ionian mode is in the key of G and consists of following notes: G, A, B, C, D, E, F#. Other modes are derived from ionian mode and consist of the same exact notes. What matters is which note is the first, most important one.

Figure 2 is another illustration of diatonic modes on guitar fingerboard. Ionian mode is in the key of C and consists of following notes: C, D, E, F, G, A, B. Other modes are derived from ionian mode and consist of the same exact notes. What matters is which note is the first, most important one.